package cn.edu.scau.cmi.chenxiaoqin.exercise9;

public class EncryptAndDecrypt {
	String encrypt(String sourceString,String password) {
	char [] p= password.toCharArray();
	int n =p.length;
	char []c =sourceString.toCharArray();
	int m= c. length;
	for(int k=0;k<m;k++) {
	int mima=c[k] + p[k%n];
	c[k]=(char)mima;
	}
	return new String(c);}
	String decrypt(String sourceString,String password) {
	char [] p= password.toCharArray();
	int n = p.length;
	char []c =sourceString.toCharArray();
	int m = c.length;
	for(int k= 0;k<m;k++) {
	int mima=c[k]-p[k%n];
	c[k]= (char)mima;
	}
	return new String(c);
}
}
